1. Field of the Invention
The invention relates to an elastomer bush bearing with at least one axial limit stop, which limits the axial spring travel of the bearing body for spring compression for oscillations introduced into the bearing in the axial direction.
2. Description of the Related Art
It is known to equip bush bearings in automobiles, which are used, for example, for supporting the connecting rod of chassis suspensions, with limit stops of excursion limiters to limit the compression spring travel of the bearing body subjected to oscillations. This prevents excessive deformations or excessive elongation of the elastomeric bearing body from destroying the bearing. The limit stops, in particular in bearings with a soft spring characteristic, are typically designed so that the produced excursion limit is not abrupt, but starts out rather gradually. This is accomplished by fabricating the stop faces at least partially also from an elastomer. This also prevents annoying vibration effects and noise when the excursion limitation takes effect. The axial limit stops of a rubber bearing or an elastomer bush bearing of the aforedescribed type are formed by two stop faces which face each other in the axial direction and are spaced apart by a gap. The gap determines the free travel during spring compression of the elastomer bearing body, or the amount by which the rubber spring can expand until the excursion limitation takes effect. An operating range is defined for the bearing within the characteristic curve field describing the spring characteristics by specifying the possible spring excursion of the elastomer bearing body until the excursion limitation takes effect. In conventional devices, the stop elements of the excursion limiter are arranged on or in the bearing at a fixed location. If the preload acting on the bearing changes, for example when the vehicle load is increase, the operating range of the bearing disadvantageously shifts within the bearing damping curve toward the progressive branch of the spring characteristic. Stated differently, the free travel of the elastomeric bearing spring is reduced on the spring compression side, while the free travel is simultaneously increased on the spring rebound or expansion travel side. When the preload changes, the bearing no longer operates in a symmetric operating range, with reference to the defined total spring travel of the elastomeric spring, because the limit stop of the spring body is reached sooner in a spring compression direction than in the opposite direction. This results in a noticeable deterioration in the drive dynamics and the comfort of the vehicle.